Currently, many network elements distributed in different regions are connected through the Internet. For the purpose of reducing the scale of the network and the cost of administrating and maintaining the network, the whole network is divided into different segments by routers. Network elements in the same segment may communicate with each other, and network elements in different segments can not communicate with each other directly; instead, a router is needed to forward IP packets. The communication between the network elements in different segments is realized by implementing routing protocols, such as Internal Gateway Protocol (IGP) and Border Gateway Protocol (BGP).
However, the inventor finds that the prior art exists the following problem:
When a local device communicates, via a router, with a remote device which is not located in the same segment as the local device, the router has to discover the local device according to a routing protocol, and dynamically establishes and maintains, according to information provided by routing messages, a destination IP address in a routing forward table as a table entry of the local device, which increases the overhead of the router.